Cardiovascular disease begins early in life but may be prevented or delayed by primary prevention programs designed for young people. The proposed research will develop, implement, and test a school-based multicomponent health behavior change program for 15-year old high school students. Four schools will be randomly assigned to intervention and control conditions. The intervention will be delivered to adolescents in two cohorts (Cl to begin in 09/84 and C2 to begin in 09/85). Bandura's social learning model, emphasizing skills development and performance, will provide the theoretical unterpinnings for our intervention. The proposed project is designed to indentify methods for (1) building self-regulatory skills to enable studenst to develop healthy lifestyle behaviors, (2) decreasing cardiovascular risk factor behaviors and increasing healthy behaviors, and (3) to lower risk factor variables. The program will be comprised of a series of modules designed to (1) introduce students to healthy living concepts and the value of adopting healthy lifestyles; (2) help students acquire specific information on the health risk/benefits of a variety of risk factor behaviors and practices; (3) help students to acquire cognitive and behavioral skills for changing their own behavior and influencing family and social environments; (4) provide practice in the use of these skills to bolster perceived competence in their ability to make changes successfully; and (5) provide practice in the invention and use of "resistance" skills to combat inducements to return to old habits and in consequence, to improve maintenance and generalization of new skills. Self-report measures will include: health habits survey, perceived self-efficacy, food frequency checklist, and physical activity checklist. Physiological measures will include skinfold thickness, resting blood pressure, step test, and expired air carbon monoxide.